Kantei
A short, straight blade on a black background, with a long carved groove and the rusted tang on the left with two holes.

Yamato · late Kamakura · Hōshō school

Hōshō Sadamune (保昌貞宗)

The swordsmith whom tradition holds to be the effective founder of the Hōshō school of Yamato, and the school itself: its period, the masame that gives it away and its named works

Hōshō Sadamune (保昌貞宗, Hōshō Sadamune) is a swordsmith of the Hōshō school, of the Yamato tradition, from the late Kamakura period. Tradition holds him to be the effective founder of the school, but there is hardly any information about him and no work of his with an official record has been located. That is why this monograph tells, above all, the story of the school: the one with the most pronounced masame of the Japanese sword. He must not be confused with the Sadamune of Sōshū.

Tokyo National Museum, via ColBase

1317
Active around, according to tradition
5
Schools of the Yamato tradition
3
Signed tachi of the school known in 2021
Sadaoki
His son, according to the Meikan
On this page
  1. Quick profile
  2. In short

Quick profile

Name
Hōshō Sadamune; also Hōshō Gorō Sadamune, 保昌五郎貞宗 (Hōshō Gorō Sadamune) AT
Kanji and reading
保昌貞宗 (Hōshō Sadamune) AT
Period
Late Kamakura period; tradition places him around the Bunpō era (1317). Dates of birth and death unknown AT
Province
Yamato: Takaichi district, south of the Nara basin (today Kashihara) HD
School
Hōshō, one of the five of the Yamato tradition HD
Master
According to tradition, his father, Kunimitsu (国光, Kunimitsu), of whom no work survives AT
Generations
The school continues with Sadayoshi, Sadakiyo, Sadaoki and Sadamitsu, among others; Sadaoki was his son according to the Meikan AT
Documented fact and tradition
Documented: the school, its dates and its style. Tradition: that Sadamune was its actual founder and that he was the son of Kunimitsu. AT

In short

What we know. The Hōshō school worked in Takaichi, in Yamato, in the late Kamakura period: its blades bear dates from 1317 to 1328. Its hallmark is a regular masame, straight like the grain of wood.

How we know it. From the NBTHK journal and from the official records of works by other smiths of the school. What concerns Sadamune comes from tradition: that he was the actual founder of the school, his full name and his period.

What we do not know. His dates of life and which surviving blades are his: no work by Sadamune with an official designation is recorded.

Sections

  1. Takaichi · Bunpō · Sadaoki Life and times The Hōshō school, its dates, its lineage and the little that is known about Sadamune.
  2. Masame · suguha · yakizume Work and style The kantei keys of the school, key by key, and how not to confuse it with its imitators.
  3. National Treasure · Important Cultural Property Famous works The named works of the school, all by other Hōshō smiths: none by Sadamune has been located.
  4. Bibliography and credits Sources The sources consulted on 4 October 2026, with their link, and the credit for each image.